Thermal Steam-turbine Power Plants

Large steam-turbine plants have two forms: condensing plants or electric power plants.

He great masses of hot steam, having accomplished the mechanical work in the turbines of condensing steam-turbine plants, are condensed, i.e. are cooled down and turned back into distilled water, and returned to the boiler for production of steam to activate the turbine.

Condensation of steam takes place in condensers where the hot steam is cooled when it comes in contact with tubes through which cold water, supplied from a water reservoir (river or lake), is circulated. This cooling water, after it takes the heat from the spent steam, is returned to the water source carrying alond with it the unutilized heat energy. This water is called the circulating water. The importance of the distilled water for feeding steam boilers is extremely great since chemically clean water decreases the formation of scale in the boiler tubes, and, thus, makes their service life longer.

Condensing plants of large generating capacity are built close to sources of fuel, in order not to transport large quantities of fuel over considerable distances.

The electric rower generated in such plants is transmitted over long distances for the supply of large industrial regions. So these plants are called regional thermal power plants.

Heat and electric power plants, in addition to electric power generation, also supply heat to closely located consumers (within a radius of 50 km), i.e. serve as district hest plants. To such heat consumers belong all kinds of industrial enterprises that require heat for production purposes, and also municipal consumers such as baths, laundries and the heating systems of dwelling houses and other buildings.

The electric power developed by the generators is fed to the switch-board of the plant, whence it is delivered by overhead transmission and cable lines to the consumers.

For several reasons, the relative importance of the various types of power plants has been shifting. Good sites for new hydroelectric plants have become scarce in many countries. Distribution networks have been extended so that less expensive power from large steam-electric stations has been replacing power from smaller diesel-generator units. Nuclear-electric power plants have been built instead of fossil-fuel steam-electric plants because the cost of coal and oil has been increasing.

 

 

Vocabulary.

Steam- пар

to accomplish- завершать, выполнять

to condense-испарять

to cool-охлаждать

Boiler-котел

to supply-поставлять

source-источник

to feed-питать

to decrease- уменьшать

service life- срок службы

to generate- вырабатывать

capacity- емкость, объем

to transmit- передавать

consumer- потребитель

laundry- прачечная

dwelling- жилье, жилище

to deliver- доставлять

relative- относительный

scarce- скудный

to replace- заменять

cost- стоимость, затраты

 

2. Выполните упражнения:

1)Ответьте на вопросы:

1. In what part of the power plant does condensation of steam take place?
2. Why is distilled water used for feeding steam boilers?
3. What kinds of power plants are in use nowadays?
4. What does the selection of a type of generating plant depend on?
5. For what reason are nuclear- electric power plants being built instead of fossil-fuel steam-electric plants?
6. How are plants of large industrial regions called?
7. Where is the electric power fed to?
8. Why is the importance of the distilled water for feeding steam boilers so great?

2)Употребите слова, стоящие в скобках в Participle I, Participle II или Gerund, переведите:

1. (Cool) an electric conductor results in its reduced resistance to electric current.

2. What is the name of an (insulate) material (use) to prevent an electric shock?

3. The (apply) technique brought about quite unexpected results.

4. Mica is used as a dielectric due to (have) high voltage strength.

5. The word’s first tidal power station, a plant on the Rance River in France, began (operate) in 1966.

6. Solar energy has been converted to electricity by (use) solar cells, which are semiconductor devices (produce) from thin slices of silicon.

3)Вместо пропусков вставьте предлоги: according to, because of, through, of, at, for, by, during, in, in case of, into, переведите:

1.The power transmitted … a wire is the product… the voltage times the amperage. … resistive losses, it is desirable to transmit power … low amperage and high voltage. … doubling the voltage, the capability … a given circuit can be quadrupled.

2. Devices are classed … the operation they are intended….

3. This type … aerial is useful and popular … its small size.

4. … a faulty device its readings are not to be relied…

5. Coal and oil contain sulfur … concentrations … a few percent.

6. As these fuels are burned, the sulfur is converted … sulfur-dioxide gas. … the operation … a plant, the sulfur-dioxide and other products are discharged … the air stacks, some … which are about 305 meters high.

4)Подставьте вопросы к данным предложениям:

1. The first central electric power station was installed in 1882.

When________________________________________________?

What station______________________________________________?

2. Radioactive wastes damage man and his generation.

Who(m)_____________________________________________?

What wastes ______________________________________________?

3. The use of water power and wind power began more than 2,000 years ago.

The use of what kind of power________________________________?

When____________________________________________________?

4. The cooling water is drawn from a source and passed through the con­denser.

What kind of water_________________________________________?

What ________________________________________________from?

What______________________________________________through?

Кратко перескажите текст.

Control text.